the clarke family went sailing on a lake. Their boat averaged 6 km per hour. the Rourke family took their outboard runabout for a trip on the lake for the same amount of time. Their boat averaged 14 km per hour. The Rourke family traveled 20 km farther than the Clarke family. How many hours did each family spen on the their boat trip?
Same time?
Distance=rate*time
timeClark= distanceclark/rateclark
timeRourke=distancerourke/raterourke
times are the same, and
distanceClark=distancerourke-20km
You know rates.
set the two equations equal...
distanceclark/rateclark=distancrourke/raterouke
(distancerourke-20)*raterourke=distancerourke*rateclark
solve for distance, then distanceclark
then you can go back and solve for time in the original equations